The release of steroids into the general circulation of organisms leads to highly significant alterations in patterns of behavior. This project will address the question of how steroid hormones act on single functionally-defined cells from the vertebrate central nervous system in cell culture. Three sets of experiments are planned: (1) To use immunocytochemical and in situ hybridization methods to identify, localize and learn what influences the accumulation of steroid receptors in hippocampal and other neuronal cell cultures; (2) To examine using electrophysiological, biophysical, and biochemical methods, both short-term (non-genomic) and long-term (genomic) effects of steroids on neurons in culture; and (3) To see if similar changes can be seen in intact organisms to those seen in cultured neurons, and to try to understand how such changes might influence circuits of neurons. Steroid hormones are exceptionally important substances, playing essential roles in human development, sexual and aggressive behavior, reproduction and the ability to cope with stress. The goal of the studies presented in this application is to attempt to relate any steroid-mediated changes in function seen in neurons in culture, to how such changes might contribute to the behavioral consequences of steroid actions in animals.